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220
FXUS64 KMRX 271828
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
228 PM EDT Thu Jun 27 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
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(This evening through Friday)
Issued at 227 PM EDT Thu Jun 27 2024

Key Messages:

1. A few isolated showers and storms persist through early evening,
mainly along and south of I-40.

2. Drier overnight with areas of patchy fog.

3. Back to slightly above normal temps tomorrow, along with a few,
diurnally driven, isolated showers and storms.

Discussion:

Our upper shortwave can currently be seen via satellite spinning
down across MS/AL. The bulk of the precip associated with this
feature is to our south, but we remain on the northern periphery of
this system. This means isolated to scattered showers and storms
will continue into this evening, but mainly along and south of I-40.
No severe weather is expected.

We dry out overnight as this system drops further south, along the
Gulf Coast. Areas of patchy fog are likely, especially for any areas
that received rainfall over the past 24 hours.


Tomorrow, we get a southerly return flow as high pressure begins to
develop just off the east coast. This moisture return will allow for
some diurnally driven showers and storms during the afternoon hours.
Coverage should be isolated to scattered at best. No severe weather
is expected.
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&&

.LONG TERM...
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(Friday night through next Thursday)
Issued at 227 PM EDT Thu Jun 27 2024

Key Messages:

1. Scattered showers and thunderstorms through the weekend with a
diurnal increase in coverage.

2. Drier next week with ridge building across the region. Signals
for hot weather returning.

Discussion:

Ridging continues across the Lower Mississippi Valley on Friday
night. A strong shortwave across the northern Mississippi Valley
into the Great Lakes will flatten the ridge across the Tennessee
and Ohio Valleys and bring an associated cold front our direction.
Ahead of this front, diurnal convection will be possible on
Friday, and more likely, on Saturday and Sunday. The highest
chances each day will be across the higher elevations. The NAM
shows MLCAPE of around 2000 to 2500 each afternoon with a very
moist atmospheric profile. Because of this, DCAPE will be limited
to less than 800 J/Kg. This means that the severe risk is low, but
a few damaging wind gusts could still occur. PW values are
expected to be 2.1 to 2.4 inches ahead of this frontal boundary.
Model QPF is not especially high, but this atmospheric profile
will support very heavy rain rates with stronger convection. This
could result in some localized higher rainfall totals and flash
flooding, especially with any training convection.

Behind this front, somewhat cooler and drier air is expected early
next week. However, ridging builds back in mid-week with a warming
temperature trend on Tuesday through Thursday resulting in above
normal temperatures once again. By late week, southerly flow returns
with increasing moisture and low diurnal thunderstorm chances.
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&&

.AVIATION...
(18Z TAFS)
Issued at 106 PM EDT Thu Jun 27 2024

MVFR CIGs forecast for CHA and TYS over the next few hours. Low
confidence though as surrounding sites are a mix of VFR and MVFR.
Otherwise, a few isolated to scattered showers and storms are
expected this afternoon into early evening. However, not
confident enough in amount of coverage to include VCTS in at TYS
or TRI. May have to amend if coverage is greater than expected.
Do have VCTS in at CHA until 22Z. MVFR fog at TRI overnight.

&&

.PRELIMINARY POINT TEMPS/POPS...
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Chattanooga Airport, TN             72  92  76  91 /  20  30  20  60
Knoxville McGhee Tyson Airport, TN  70  92  74  91 /  10  40  20  70
Oak Ridge, TN                       69  92  74  90 /   0  40  10  70
Tri Cities Airport, TN              66  90  71  90 /   0  30  20  70
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&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$

SHORT TERM...
LONG TERM....JB
AVIATION...